Rawalpindi , Pakistan -LRB- CNN -RRB- -- A suicide bomber killed at least 35 people Monday by detonating explosives outside a bank where people had lined up to pick up their monthly checks , police said .

The blast , in the Cannt area of the city , also wounded more than 65 others , said Imdad Ullah Bosal , a district coordination officer . Two women were among the dead , he said .

Meanwhile , another suicide bomber detonated his explosives at a police checkpoint in Lahore hours after the Rawalpindi attack , a police official told CNN .

The bombers , believed to be wearing suicide vests , blew themselves up as police inspected their vehicle at the Babu Sabu checkpoint , according to Lahore police chief Pervez Rethore . The blast injured at least 17 police and civilians , a local rescue services spokesman said . At least three people sustained serious injuries , Rethore said .

In recent weeks , Pakistan has been rocked relentlessly by a wave of attacks as Islamic militants retaliate against a military offensive to rout insurgents operating along its border with Afghanistan .

The worsening situation prompted the United Nations to announce Monday that it was pulling all non-emergency foreign staffers from the country 's northwest .

The scene of Monday 's deadly explosion in Rawalpindi is about 18 miles -LRB- 30 kilometers -RRB- from the capital city of Islamabad . It is a closely guarded city that is home to the country 's military headquarters .

The Cannt area is short for cantonment , so called because of its proximity to the military offices . It is home to several travel agencies and mid-range hotels .

The bomber rode up to the front of the National Bank in a motorcycle or a bicycle , said Rawalpindi Police Chief Rao Muhammad Iqbal .

The impact of the bomb was so intense that residents a block away said they thought the blast took place where they were .

The explosion blew out windows in the three-story building and blackened its walls . Rescue workers in surgical masks picked through the rubble looking for survivors .

Iqbal Nisouwana , a driver , who rushed to the scene to help tend to the wounded said he saw five men in uniform among the wounded .

`` Two soldiers were injured . I helped put them in the ambulance , '' Nisouwana said . `` And I saw three more wounded . ''

`` One old man called to me for help , '' he added . `` I tried to pick him up but he was too heavy . ''

On October 10 , militants held dozens of hostages for some 22 hours inside the army headquarters in Rawalpindi . Eleven military personnel , three civilians , and nine militants were killed in the siege .

On October 20 , back-to-back explosions took place at Islamabad 's International Islamic University . At least six people died in the attack . Twenty-nine others were wounded .

And on October 28 , a massive car bomb tore through the heart of a bustling marketplace in Peshawar , killing at least 100 people and injuring at least 200 others .

The attack on the capital of the North West Frontier Province was the deadliest terrorist attack on Pakistan since the October 2007 attack on a homecoming rally for former Prime Minister Benazir Bhutto . More than 135 people were killed in the suicide bombing in Karachi . Bhutto escaped harm , but she was assassinated two months later .

Her husband , Asif Ali Zardari , is now the president of the country .

The U.N. decision to withdraw staffers applies to all except those needed for emergency , humanitarian and security operations in the North West Frontier Province and the Federally Administered Tribal Areas -LRB- FATA -RRB- , said spokeswoman Ishrat Rizvi .

The agency has been providing aid to the 2 million Pakistanis who have been displaced in the fighting between government forces and Islamic militants .

This year , the United Nations has lost several staffers to terror attacks , including five who were killed in a suicide bombing at the World Food Programme offices in Islamabad last month .

Two more U.N. workers died when attackers shot their way onto the grounds of the Pearl-Continental Hotel in Peshawar in June and set off a car bomb .

And gunmen killed a U.N. worker during a kidnapping attempt in Peshawar in July .

CNN 's Ivan Watson in Rawalpindi , Samson Desta in Islamabad and journalist Nasir Habib contributed to this report .

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Death toll reaches 35 , with 65 wounded , authorities say

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Suicide bomber detonates explosives outside a bank in Rawalpindi

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Bomber rode up to the front of the National Bank in a motorcycle or a bicycle

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NEW : Second suicide attack in Lahore injures at least 17 people